Desmodesmus is one of the most abundant coccoid green algae in
fresh and brackish waters all over the world. Once considered a subgenus
of Scenedesmus, it was recognized as an independent genus
based on 18S and ITS2 rRNA gene [4–6]. The Scenedesmaceae, to
which both Desmodesmus and Scenedesmus belong, is noted for its
distinct coenobium (a clonal colony of cells) and wide distribution
in freshwater ponds and rivers and in brackish waters. However,
they exhibit complex phenotypic plasticity and remain in taxonomic
uncertainty until today [7]. Our current observations revealed single
cell clumps forming green spots instead of the typical coenobium.
Each cell exhibited small surface warts, a characteristic substructure
in Desmodesmus, in contrast to the smooth, non-ornamented cell
surfaces found in Scenedesmus [8]. Both molecular and morphological
evidence supported their identification as a species of Desmodesmus,
and particularly D. komarekii, a species found in freshwater lakes or
ponds [9,10].